Sections of the primary structure of nylon and the primary structure of a protein are shown below - VCE - SSCE Chemistry - Question 3 - 2012 - Paper 1

The functional groups that link the monomers in nylon are the amide groups (–C(=O)–NH–), formed from the reaction between the amine (NH2) of one monomer and the carboxylic acid (COOH) of another.

The functional groups that link the monomers in protein are primarily the peptide bonds. These bonds are formed between the amino group (NH2) of one amino acid and the carboxylic acid group (COOH) of another.

In proteins, the functional groups that link monomers (amino acids) are oriented in the same direction to maintain structural integrity and allow for specific folding and functionality. This is crucial for the protein’s biological activity. Conversely, in nylon, the functional groups linking the monomers are oriented in opposing directions. This different orientation allows for a linear polymer structure, which contributes to nylon's strength and durability. The difference in orientation is attributed to the specific chemical reactions involved in polymerization, as amide bonds in nylon can be formed in alternating directions.

A section of the polymer, polymethyl methacrylate, incorporating at least two units of the monomer can be represented as follows:

   H   O   H   O
   |   ||  |   ||
  C-C-C-C-C
   |         |
  H         C-CH3
             |
             H

This depicts the repeating units of the methyl methacrylate, showing the ester linkages formed during polymerization.